"Ozone is now a round-the-year problem requiring urgent attention of clean air programmes," said CSE executive director Anumita Roychowdhury. Another expert said that the number of days not meeting the ozone standards is increasing even in winters. The assessment has traced trends during different seasons – summer (March-June), winter (October-February) and monsoon (July-September), between 2018 and July 18, 2021. In 2020, Delhi had 115 'good' days, which was 24 days less than in 2019," it said. The analysis found that ozone build-up is a hyper-local phenomenon as there can be 100 micrograms per cubic metre (µg/m3) difference in ozone levels between two neighbouring stations.

Source: Mint July 30, 2021 16:52 UTC